Motoya Nakamura / The OregonianJapanese troops clean up and monitor traffic Friday around a four-story building knocked over by the March 11 tsunami in Onagawa, Japan. Oregon State University expert Harry Yeh says the building's unexpected failure upends standard and advice and precautions concerning tsunamis.

ONAGAWA, Japan -- Oregon State University tsunami expert Harry Yeh thought he'd seen every kind of damage a giant wave could inflict, until a sight in this devastated fishing town stopped him cold.

Here amid crushed cars and mangled houses, a four-story reinforced-concrete building rests on its side like a toppled domino, knocked over by the March 11 tsunami that soared 60 feet high. Yeh says the fate of this building upends the global science of tsunami preparation and evacuation.

Yeh has visited virtually every tsunami zone from Nicaragua in 1992 to the Indian Ocean in 2004. He believes the failure of the Onagawa structure, which housed living quarters above a CD music store, will cause revised recommendations for construction and escape strategies on the Oregon coast and other tsunami-prone areas. Yeh and Steven Kramer, a University of Washington earthquake expert who traveled to Japan with him last week, say the Northwest could be far better prepared.

"Up to now, we thought reinforced-concrete buildings were safe," Yeh said. "So we recommended to people that if they don't have time to escape a tsunami, find a reinforced-concrete building and climb up to the fourth floor."

Japan is widely considered the best prepared nation in the world for tsunamis and earthquakes. It emerged largely unscathed from the magnitude-9 quake that triggered last month's tsunami.

Yet the monster waves that left more than 28,000 dead or missing shattered not just cities but estimates of the outer bounds of destruction. Scientists, engineers and architects examining apocalyptic damage along miles of Japanese coastline are recalculating the enormous power of water set in motion by quakes.

Residents of Onagawa, a fishing port east of Sendai, Japan, say the tsunami appeared on the horizon like a vast dome of water spanning the bay. The giant wave roared into town, devouring ships, houses and everything else in its path. Then the water retreated, sucking cars from elevated parking lots and depositing some atop buildings. More towering waves followed.

"There were people who went up to the tops of three- and four-story buildings," said Hiroshiko Oka, a bar owner who watched from a hilltop shrine. "They got killed."

Oka, 52, watched bank employees emerge on the roof of their three-story office building, scaling a rooftop stair enclosure one floor higher. But the tsunami crested the building, pitching a dozen people -- some of them Oka's childhood friends -- to their deaths. One survived.

Oka, whose tavern behind another tipped-over building was demolished, said it was the tsunami's first monster wave that knocked over structures, including the reinforced-concrete building that Yeh considers so significant.

A cell-phone video recorded by a local medical worker shows people who reached the roof of a nearby five-story building surviving the tsunami. That building did not tip over.

Yeh pointed out that many reinforced-concrete buildings in Japan's tsunami zone remain standing. He said lots of people were saved by "vertical evacuations" to floors above the tsunami, which reached widely varying heights at different points along the coast. So the unexpected failure of one building doesn't necessarily negate all advice on tsunami preparation and survival.

But Yeh remains troubled by the toppled building. He's stunned, even with all he has seen of past tsunamis, by the massive scale of damage in Japan. "The Sendai plain, it's so vast it's just incredible," he said, referring to a devastated expanse in the tsunami zone. "I'd never seen this type of site before. I was totally, totally stunned."

"Then I saw this Onagawa site," Yeh said, referring to the city with the overturned building. "This is just incredible."

The toppled edifice made Yeh think of reinforced-concrete buildings -- or rather, the absence of such structures -- on Oregon's coast. The Seaside parking garage is one. The five-level structure has interior shear walls with seismic reinforcement. Coastal communities should consider reinforced-concrete buildings in new construction, especially for public structures, Yeh said.

Yeh studies flow-structure interactions and tsunami-induced scour. He plans to research ways of preventing buildings from tipping over.

Yeh's colleague from Seattle, the UW's Kramer, said tsunami-hazard awareness and evacuation planning have improved along the Oregon and Washington coasts, especially since the 2004 Indian Ocean tsunami, which killed 230,000 in 14 countries.

"Still," Kramer said, "after seeing tsunami debris hanging on the sides of hills some 60 feet over my head -- and cars on top of four-story buildings -- in Onagawa, I doubt that the general public is fully aware of just how bad things can get."

As an earthquake expert, Kramer said the key question is why the magnitude-9 quake did such little damage. He said Japan's numerous seismometers have yielded the best-ever picture of ground shaking and where it occurred. The ground shook longer and harder than the 1995 quake in Kobe, Japan, which collapsed 200,000 buildings and an expressway, killing more than 6,000.

Japanese building codes and earthquake awareness are partly responsible for the lack of damage, but there are structures built well before code improvements that performed relatively well, Kramer said.

"If it wasn't for the tsunami," Kramer said, "I think the Japanese would be considering the damage of this earthquake to be a great success story."

Kramer said the Northwest could be far better prepared for earthquakes, let alone tsunamis.

"The Northwest is much less prepared than California, and California is much less prepared than Japan," he said. "Part of that is human nature -- the Japanese are reminded that they live in earthquake country all the time, and we aren't," Kramer said. "Their governments and private firms have also been willing to invest in earthquake-resistant infrastructure and earthquake preparedness. Ours haven't."

Kramer and Yeh traveled Japan's northeast coast with other U.S. experts on a mission to guide larger U.S. teams expected to arrive here shortly. They visited Tokyo, Ichinoseki and the devastated coastal cities of Onagawa, Sendai, Kesennuma and Rikuzentakata.

Yeh said Oregon's geography resembles northeast Japan, with many isolated coastal communities separated by a mountain range from a valley with highways. Like Japan, Oregon faces an undersea subduction zone, in which an oceanic plate pushes beneath a continental plate. Japan's offshore trench is far deeper.

"We do not know what kind of rupture process we're going to have" for that Cascadia zone, Yeh said.

Yeh worked previously on nuclear power-plant engineering. He said the Fukushima Daiichi nuclear complex hit by the tsunami and leaking radiation is a product of old technology. "Forty years ago, they did the best they could do," he said. "This tsunami was beyond the predictions."

Nuclear plants could be located away from tsunami zones by storing cooling water on higher ground, Yeh said, instead of using a once-through ocean coolant system. Earthquakes would still be an issue, he said, but not tsunamis.

Yeh, 61, has Chinese and Japanese ancestry. He grew up in Japan and speaks Japanese. He said he became emotional at times last week, touring the tsunami zone.

"The Japanese will probably rebound from this event," Yeh said. "They've done it before, from the war."